My sister is Rh neg and only received the standard 2 injections. She had reg af on all 3 of her pgs for the 1st few months, too. She has never mc. I suppose if you have rejected an embryo or fetus due to the Rh factor in the past, they may administer the Rhogam. I do not know the criteria.
I'm 22 weeks pregnant and Rh neg. I did not receive Rhogam after spotting. I actually had spotting until 14 weeks. I think I receive Rhogam at 28 weeks and after delivery.